French fry oil temperature

Whilst partaking of a fine meal at McDonalds, my brother offered this nugget of trivia: He’d read that the temperature of the oil used to fry the fries was a closely guarded trade secret. Is this true? Do you know what that temperature is, and if so can you tell us? In any event, what difference does the temperature make anyways?

350 degrees F, give or take. It’s no secret. The oil has to be hot enough to cook the fries quickly without making them mushy, but not so hot as to start smoking or catch fire. This encompasses a fairly narrow range of temperatures from about 300 or so to just over 375. Deep fried foods will always be cooked somewhere within this range.

And french fries cooked twice, once in oil at 325F until tender then at 375F until crunchy are the best IMHO.

You got it, Duke of Rat. They’ll always come out perfect that way.

In fact, I believe that frozen fries are frozen after the first lower temp cooking, and one puts them directly from the freezer bag into the 375 oil. Does McDonald’s use frozen fries?

Yes. But they are uncooked at the time they are frozen. I’ve never heard of fries being cooked prior to being frozen, or am I misunderstanding you?

What period of time between the two temperatures? Do you let them cool down first? Do you have two vats and just transfer from one to the other? Do you just turn up the temperature in the one vat?

About 3 or 4 min at 325. You can drain them and raise the temp if you don’t have 2 vats handy, doesn’t really matter. You are just cooking them to soften them up.

Here is a Food Network article that has them drained between cookings. I think I learned the technique from Julia Child, and she went from one oil directly to the next IIRC.

No, you didn’t misunderstand me. The very few times I’ve bought frozen fries, they were pretty obviously semi-cooked before being frozen. At some fast food joints, I’ve seen them opening big brown paper bags of frozen fries that look just like those pre-cooked grocery fries. McDonald’s, however, might do things differently. For one thing, their fries are almost “shoe-string” fries, which are thin enough that they may not need the double-cook method to stay crisp.

McDonald’s fries come cooked to the store (partially fried, to get them partially done in the middle.) I can’t say that I know what temperature that is. They’re frozen, but McDonald’s aims to fry them an hour after they’ve been out of the freezer. They’re good for (I believe) 2.5 hours after they’ve been pulled from the freezer, then apparently they’re too warm to fry properly. No one cares at the store level because we can’t tell the difference, and the fry hopper turnover is usually fast enough to where it doesn’t matter.

I can say that the fryers in the store cook the fries at 335 degrees for approximately 3 minutes and 10 seconds. (That’s the start time for the fryers, different stores may have different recovery times on the oil, or different thermostats, so that they need different cooking times by maybe 10 or 15 seconds.)

Next time you’re in the store, ask an employee for a frozen, uncooked fry, and you’ll see that it’s already greasy, as though it had been fried already.

Back in the day:

Indeed, McD’s used a two step process: first cooking at a lower temp to force out the water in the spuds and infuse them with lard. Then later, when fries were needed, cooked at a higher temp to golden crispness.

You’d spend a good part of the afternoon blanching fries in baskets so you would have some ready for the final cook during rush hour.

As to secrecy, you’ve got to be kidding me. The temps were on the dials on the fryers and 15 year olds were running the thing. Hardly a “Top Secret” operation.

Using thin-cut fries is key to getting this right. I am baffled at how many places don’t do the double frying or use thick cut fries (or both).

The temp is no closely guarded secret…it is 365 for their oil which by the way was temp of the grill for hamburgers, I know as I worked there 30 years ago. Unless it has changed that was the required temp of the vat. The Fries came frozen pre-cooked. We used Mc-Lard at that time but it changed to Mc-Shortening.

Heston Blumenthal’s triple cooked chip is supposed to be very good. He boils the chips until they are cooked through, fries at 250 but doesn’t let them brown, and fries again at 375. He also sticks them in the fridge between each step so they dry off. This supposedly results in a crispy chip with a soft, fluffy inside.

I thought old school McD’s fries were cooked in tallow/beef fat, not lard.

Actually, McDonald’s has a more involved process than you might think. (Look under “Deconstructing the Arches”)The cut fries are first blanched for about 15 minutes in 170 degree water, then fried in 365 degree oil for 50 seconds.

From there, they’re frozen and shipped to the individual restaurants who refry them at some temp approaching 375.

In essence, they’re re-frying something akin to the Ore-Ida fries you can buy in a bag at the grocery store, albeit made to their exact specs.

My High School Summer Job at the Burger Joint was at something called “Burger Chef”.

We got in fresh potatoes, took all of 10-15 minutes to run them through the peeler and then the slicer.
We then blanched a bunch for the night shift.

If that tiny going-nowhere joint could do real fries, why does everybody use frozen crap?

In-N-Out makes a huge deal of putting the potato prep in clear view of the customer.

No, the infamous Hindu lawsuit (bunch of mislead vegetarians) was that they were cut and seasoned and coated in beef tallow before being put in those frozen bags as part of the factory prep. The oil in the fryers was just giant bricks of some sort of shortening, IIRC.

The good restaurants try to avoid mixing the fish fryer with the chicken or fries. IIRC chicken was at a slightly lower temperature.

This says they were:

They do indeed. And their fries suck. Best burgers in the business, though.

Yeah, In-n-out was a total let-down for me after reading all of the Internet Hype. the burger was fine, but nothing special, and the fries were terrible.

Even ordering them “well done,” as has been suggested to me, is a let down. Maybe “animal style” would improve it, but I don’t need all those extra calories. I just skip their fries. But their burger is my platonic ideal of a fast food hamburger (and so friggin cheap!) and what I aim for every time I make mine. I’m just glad there aren’t any even remotely close to where I live, as I’d be 25 pounds heavier.